1. Technical Field
The present invention relates generally to a virtual server and a virtual machine management method for supporting a zero client and, more particularly, to a virtual server and a virtual machine management method for supporting a zero client, which provide the host interface of a virtual machine by selectively using any one of emulation mode in which a shareable host interface set is emulated to generate a virtual host interface set and direct connection mode in which a directly allocatable host interface set is connected to the zero client, thus serving high-end level applications such as three-dimensional (3D) games, high-quality video, high-quality audio, and 3D graphic tasks.
2. Description of the Related Art
A method of generating a virtual host interface having a 1:N relation with a physical host interface so as to provide a unique physical host interface to a plurality of virtual machines in a server virtualization environment is referred to as “emulation mode.” Here, an Operating System (OS) installed on each virtual machine recognizes a virtual host interface set generated by virtual software as its own host interface and is then operated by the virtual host interface set. Such virtualization technologies include CITRIX XenServer, MICROSOFT HYPER-V, VMWARE ESXi, ORACLE Virtual Box, GNU Open License-based Quick EMUlator (QEMU), etc.
However, in the case of a host interface that duplicates large-capacity data such as for a Video Graphics Array (VGA), a Universal Serial Bus (USB) device, or a sound device, or that requires the ability to exclusively use a processor for a relevant device, the load of the processor greatly increases and the performance of an application being executed using the host interface cannot be guaranteed when the device is being processed in emulation mode. Therefore, it is impossible to smoothly provide services such as high-end level applications (3D games, High Definition (HD)-level video, etc.) that are executed using such a host interface. Processor technologies, such as INTEL VT-d or AMD Input/Output Memory Management Unit (IOMMU), relate to a device for directly allocating host interfaces to virtual machines in a 1:1 manner, and the scheme of this device is called a direct allocation scheme. Therefore, virtual machines can smoothly serve high-end level applications by directly connecting some host interface devices to the virtual machines using such a device.
In order to provide a virtual desktop service in a server virtualization environment, Input/Output (I/O) signals of a virtual machine must be able to be represented or controlled by a remote client. Conventional technologies for processing I/O signals of a virtual machine include MICROSOFT Remote Desktop Protocol (RDP), CITRIX High Definition Experience (HDX), TERADICI PC over Internet Protocol (PCoIP), VMWARE VIEW, etc. In these technologies, I/O signals of a virtual desktop are transmitted in a digital format using a network protocol between a virtual machine and a client. Here, the client is equipped with a processor and is then configured to process the I/O network packets of the virtual machine and to represent the desktop of the virtual machine using its own host interface device. That is, the client has the form of a computer which includes a processor, a host interface, and an I/O device and on which an Operating System (OS) is installed.
Conventional methods for remote virtual desktop services in the virtualization environment are configured such that digital I/O signals of a virtual machine must be represented and controlled by a client using a network protocol. For this, the devices of the client must include a processor, a host interface, and an I/O device. Therefore, a problem arises in that the production cost of the client increases, and the load and the processing time of the processor occur because of having to generate network packets by attaching I/O signals of the virtual machine or having to extract I/O signals from network packets.